Tool driving apparatus



Oct. 13, 1931.

G. E. SMITH 1,827,269

TOOL DRIVING APPARATUS Filed July 30. 1928 2 Sheets-Sheet l I v r 6 i I '1 uuento'o @511; W WM Patented been, 19311 GEORGE E. SMITH, or r hrtx m nesmmuc rss iroa 'ro II-IE UNITED smiths n "moor mmm APPARATUS Apisneatipn enemy so, 1928." Serial No. 296,200."-'$

- Thisiinvention relates ito toolidriving apv paratu's of the portable type, and is particu larly directed to a eomloination power driven and manually operated tool dr ving device incorporating vsafety A features. The i use, of v t vpower for v actuating 'a toolsuCh, as a; wrench.

orv screw driver, is of extreme advantage estheparttoybeiastenedk T It is necessary in theuseoi power in. driving certain'tools to; automaticallydiscontinue I the drive aft-era certain pressure or'force is 'exertedjon: the nut orbolt, otherwise unlimited power would strip; the, threads; .Where f there, is a wide range in the size ofthetool,

used 'with i the "device; it isof considerable 3 difficulty; to determine and Tarra'nge for an v automatic drive discontinuation since-the -necessaryyvary greatlydn-z given pieces of w k 7 -1 5 o al power 30 Y V p and in which the drive will be automatically size of the bolt 0r nut, the coarsenessiofiv the thread; the length thereof: andr thetightening I 'It has;thereforey'heen extremely diflicult to design aipower driven tool which would: draw-F the parts up to the proper de It object olf to' 'provide. driven portable tool fflvvhich will I quickly draw :up gthe' anut-,-"'bolt",yscrew, v et c.,,

discontinued as the "same pressure .I orf degree 01f force .isiexerted'; on t'he work in all instances: *tThat :to say; this invention coni templates the provision of power means for quickly drawingiiup when or -nut: but; ren- .,dered' incapable otexerting' agtightening iforce thereonawaqv ltlis a further-objecttogprovide in north hination with" the controlledlipow'er drive a device for connecting the tool fe conven- -mientmanual actuati'on thereof.

- bealternatelynsedeither for? ei dy p werf drive or which may beused for afhand driye with an te t moremeetl nw rq etel'tli r the accompanying drawings forming a part.

in, andto p rovide thatthe changes invmode v:

of drive are quickly and convenientlymade by shifting the driven tool carrying element.

Still anotherohject is topiovi'de a clutch. controlledpower, driven mechanism forfla device of this nature which is reversibleas to 1 the direction of the drive.

Lpecially concerning the itemof speed in pri- Aiiother objectJis to providean improved -marily "drawing: up thel.bol t ,--,fnut' or -screw to attaching meansfor l the Various toolsf Use d7 incombination'with the device, i H a Another object is to provide a novelf arvnangernent for a transmitted drivereversal. Other objects andfu-rther advantages will I be more.fullyv setlforth -in,a description of of this specificatiom' in which:

Figure 1 is aside elevationfof a mentl' t Figure 2 is' atop plan view of Figure 1. g Figure 3' is a sectional view takenon line ;.3 3;- Figure 1', detailing the clutch and the Y I {means for converting thedrive from power :2 to manual operation. 4

Figure t is a section driven clutch "member; Q-

1 a Figure 6'. is' seet'ionaLview taken 6ft Figure 3,1 illustrating the arrangement oft'he teeth on the stock'of the device and I relative position of thecompanion teeth of the clutch element thereto. i

3, showing one side ofthe drive and illus Itrating th'e'driven clutch member or tool holding spindle in' cionnecti'on foi" apower drive.

Referrim to the "en'eral views of the draw m 5 Mb t I ,lngs, the var ouscaslngsof the deviceare se 7 cured together in T-sha'ped assemblage. :The

motor jand' its'j casing indicated at 1", and" the handle "2 extending from the motor easing 95 I.

and'contalningthefstartingswitchgconstitute thejshank of the T {shaped casing arrange "The electrical connection";-for;; the:

W t v moto 'extends'from the end, ofthe handle and p v tool driving vapparatusincorporatingthepresentimprover alview taken on line ii Figure 3, detailingvthe. power transmis sion tothe driving clutch member.

Figure, we a Sect'i0nalview takeh-Onlillfl t 5-5 Figure r3',"sho'vvingthe means} foratta'cl'iingtheftool'withinthe desired spindle 0111 80 taken similar to Figure I i shaft protrudes from the motor casing into acasing 6 forming the head of the T or the tool stock for housing various clutch and transmission elements making up a two direction drive. A gear 7 is secured onrthe outer end of the shaft 5 and is in mesh with a gear 8 keyed to a drive shaft 9 also jo-urnalled in the motor casing end wall at one end as at 10 and in the casing 6 at the other end in a ball bearing 11. g V

The shaft 9 has a worm 12 formed intermediate thereof in mesh with a worm gear 13 rotatabl'y journalled axially of the casing 6 (see Figure The casing 6, for the purwrench in this instance. The cap 22 has a pose of assemblage, is made in two sections secured together byscrews 14, the assembled casing 6 being secured to the motor casing by means of screws 6 traversing the base flange 6* of the casing.

v The worm. gear 13' is keyed to a double faced clutch element 15, this element being mounted at either side of the worm gear in a pair of sleeves 1616 rotatably journalled within the bore of the drive housing casing 6. The driving clutch element presents a pair of diametrically disposed teeth at each end thereof.

Tool holding spindles or driven clutch members 17 are rotatably translatably mounted in the respective end regions of the stock casing 6 providing a two direction drive and alternately engageable with the driving clutch element 15. Inasmuch as the respective driven members or tool holding spindles for each direction of drive are the same in either instance, the description will be confined to one side. The tool holding spindle provides a shank portion 18 and a head 19, the shank being slidably mounted in the bore of the sleeve 16 relative to the respective driving teeth of the clutch element 15, and theheaded end 19 being slidably mounted in the bore' of the casing 6'.

Teeth 2O companion to teeth 21 of the driv' gardless of the pressure exerted to hold them in engagement, when the driving force needed has reached a certaln degree.

A cap 22 is screwed into the end of the casing 6 and has a series of inwardly disposed teeth 23 formed thereon. These teeth are circumferentially disposed and are adapted for registry with companion teeth 2& formed on the outer face of the headed end of the tool holding spindle 17.

The member 17 is normally held out of engagement with the motor driven clutch element by means of a coil spring 25 under compression between the outer end of the sleeve 16 and the inner face of the head 19. The spring thus holds the tool holding spindle teeth 24 in engagement with the teeth 23 formed as a part of the casing.

The registering teeth or companion teeth 28, 24:, in each instance provide a straight, sharp tooth edge engagement for a positive rotative. engagement in one direction and an inclined surface in the instance-of the teeth 28 for disengagement of the teeth in the opposing direction.

The tool holding spindle 17 has: a square bore extending therethrough indicated at 27, providing a socket for the toolshank 28 carrying the desired tool 29-, indicated as a socket central bore providing a clearance: for the rotating shank passing therethrougla. The shank is limited as to: insertion into the socket by engagement with a. cross pin 36) diametrically secured in the member 17 toward the inner end thereof;

The shank is held or maintained in place within the socket by means of a detent 31 disposed within the shank and engaging a radially disposed orifice formed in the tool holder and indicated at32; The. varioustools may or may not be an integral part of the shank.

.The operation of the device is as follows:

When the switch'control for the; motor is thrown, the worm gear and driving clutch element are set in motion presenting alternately engageable driving clutch faces; The: tool: is: engaged with the head of thescrew to be drawn up or with a nut, as the case may be, and the entire device is forced downward- 1y (see Figure 7):, this action translating the respective tool holding spindle and engaging;

the teeth thereof with the teeth of the driving clutch element.v I

When the 'rotative drawing upprocess has proceeded to the point where the resistance against rotation of the spindle is; great enough;

to cause the inclined teeth edges to become disengaged, the power drive will then be discontinued and any amount of downward f'orceapplied will be ineffective to tighten the respective screw or nut. The translatable clutch element or spindle is then released from its depressed position and engages the teeth formed in the cap as a part of thebody of the device. The operator then rotates the center of the casing 6" using the shank of the T-shaped casing as the lever; and a manual tightening force is exerted on the screw or bolt.

Due to the facttha-t the engagementof'theentire device on a center coincident with the teeth this time on straight, sharp tooth edges, this manual tightening force may exerted to completely tighten the-parts until adjacent clutch teeth of'said driven element, f

" said spindles, out "of engagement with the V I V driven element and in ratchet engagement,

" 5 and a. handle extended from the shank of the the Spindles mto agement with the drivenv element. e a r.

-' In witness whereof,

. J'YEGEORGIE n's MirH. Q

it is deemed that the parts are "sufficiently tight. This manual tightening may be accomplished by using the ratchet formed by the sprlng pressed engagement of the te'eth' 23, 24, the teeth 23 being of saw-tooth forma-- tion for disengagement from the opposing teeth upon attempted reverse rotation.

By virtue of this mechanism, a power drawing up and amanual tightening is possible, with the change from one direction drive to another very conveniently made by turning the device over. The discontinuing of the power drive is rendered automatic to safeguard the screw or parts from breaking under power tightening forca y,

The views of the drawingsshow the device in position for'loosening a screw To reverse the action or tighten the screw theoperator turns the device over, that is to say, rotates it on the axis of the motor casing portion. The result of this is-thatthe drive line through the tool stock isupset end'for end and with 'aonedirection motor, a drive reversal ispossible.

Having described Atool drlvlngdevice of the class described 7 comprising a T-sh'aped casing, a power device located in the shank of said T-shaped casing,

a driven element connected to said power device and rotatably mountedin axialalignment with and within the h'eadof thQ'T-.

shaped casing, said driven element having disposed towardthe respective,

clutch teeth ends of the head of said T'-shaped casing, tool spindles reciprocably mounted in the respective ends of said head and each including clutch teeth engageable with the respectively said spindles each-having ratchet teeth at theirouter ends, said casing including ratchetv teeth formed inwardly at the ends of saidv 7 head thereof for engagement with the respectively adjacent ratchet teeth of said vdriven element, springs ,for normally maintaining T-shaped casing for oscillating the said casing on the axis of thehead for manipulation of a particular ratchet for manually operatv n ingthe particular tool-wherebythe tools may be manually operated in normal 'spring'urged position or power actuated-by depression of my name.

hereunto subscribe I 

